During various downhole operations, it is often desired to determine the radial orientation of one or more components downhole. In the exploration and production of hydrocarbons, conduits often extend considerable depths into the subsurface. These substantial subsurface distances often complicate determining the orientation of various components downhole.
One example of a downhole operation that sometimes requires determining the radial orientation of one or more downhole components is perforating downhole conduits. Perforation is the process by which holes are created in a casing or liner to achieve efficient communication between the reservoir and the wellbore. The holes thus created from the casing or liner into the reservoir formation allows oil or gas to be produced from the formation through the casing or liner to the production tubing. The most common method of perforation uses a perforating gun equipped with shaped explosive charges.
As might be imagined, it is often desired to perforate a conduit in a radial direction away from certain sensitive downhole components. For example, some wells include cables running along the length of the conduit or tubing for transmitting power, real-time data, and/or control signals to or from surface equipment and downhole devices such as transducers and control valves. To avoid damaging the cables during perforation operations, it is necessary to perforate a conduit in a radial direction substantially away from the cable. Other sensitive devices or apparatus may be installed on or in proximity to a conduit to be perforated. In such instances, it is naturally desired to avoid damaging the sensitive devices due to perforating in the direction of a cable or other sensitive device. In some instances, it is desired to perforate a conduit away from the radial direction of another adjacent conduit.
Other applications that benefit from determination of the radial orientation include, but are not limited to, certain treatment operations and logging operations. Accordingly, determining the radial orientation of one or more downhole components is advantageous in many scenarios.
Many conventional devices have been proposed to determine the radial orientation of downhole components but each of these conventional tools suffer from a variety of disadvantages.
One example of a conventional tool is the magnetic mass tool. This approach requires installation of an additional magnetic mass in the form of a cable laid next to capillary lines to provide magnetic susceptible mass sufficient to be logged by a rotating electromagnetic logging tool. The currently used electromagnetic tools and procedures are not robust and suffer from poor accuracy, which often lead to undesirably perforating sensitive external components. In addition to poor accuracy, these devices suffer from tensile loading limitations, the need to take time-consuming stationary readings, magnetic susceptible mass requirements among other limitations. These magnetic mass tools also require good centralization within the conduit since minimal changes in distance can profoundly affect readings of the tool. Poor centralization of the tool often yields false positives resulting in perforation of a conduit in an unintended orientation.
Another conventional approach is to install perforation guns on the outside of the conduit to be perforated before the conduit is installed downhole. This alternate configuration undesirably requires a larger borehole to accommodate the perforation gun. Moreover, failure of the perforation gun in this scenario is much more significant as no ready solution is available to address this failure mode.
Other conventional tools require the use of radioactive markers or injecting the cable with a radioactive fluid. The use of radioactive markers and fluids present significant health, safety, and environmental concerns. Radioactive materials pose safety and health risks, particularly on the surface before installation downhole. Such radioactive materials typically require onerous permitting, logistics, and other significant regulatory hurdles to be met. Additionally, disposal of radioactive materials presents other challenges in addition to high costs. Accordingly, using radioactive materials and fluids above surface involves many disadvantages.
Accordingly, there is a need for enhanced radial orientation detection devices and methods for detecting radial orientations of one or more components downhole and/or perforating conduits downhole that address one or more of the disadvantages of the prior art.